The invention relates to improvements to projectiles, notably of grenades, designed to be launched by means of a weapon, for example a rifle, utilizing conventional bullet cartridges.
Known projectiles of this type are generally provided with a head containing an explosive charge, this head being extended by a tubular tail capable of being mounted on the barrel of a rifle.
In a first application, a projectile launching mode requires the utilization of special propulsion cartridges without bullets, which causes difficulties at the level of the Army Service Corps, a lack of operational efficiency when a normal cartridge is used in the rifle for launching a projectile, and a serious danger for the operator in case of mistake in the choice of ammunition or the condition of the weapon with the launching of a projectile.
In another application, the launching of projectiles can be achieved with the assistance of a normal bullet cartridge, nevertheless, such an application requires a bullet trap provided in the tubular tail.
These bullet traps are generally of delicate construction and onerous for they must, with maximum security, catch and hold the bullet when a shot is fired without pernicious deformation, even rupture, of the aforementioned tubular tail. In order to absorb the kinetic energy of the bullet as well as the heat resulting from its capture, without deformation of the tail of the projectile, these bullet traps consist of a succession of screens designed to slow down and to immobilize the bullet or they consist of rather considerable metallic masses. These bullet traps have, among others, the disadvantage of a not inconsiderable weight and encumberance.
In yet another application the launching of projectiles can be achieved by means of a normal bullet cartridge, the projectiles for this purpose having, from one end to the other, an axial passage permitting the bullet to traverse the projectile or grenade and to escape to the exterior.
Applications of this type are described in the French patent no, 1.599.491 as well as in the German patent application no. 25 54 049.
This alluring conception offers the disadvantage of causing a loss of efficiency due to the fact that the propulsive gases can also escape from the aforementioned German patent application no. 25.54.049 -- a complex obturating mechanism designed to obturate the aforementioned bore immediately after the passage of the bullet. From the point of view of economy, such an obturation device is probably not less onerous than a bullet trap. Moreover, as this obturator only begins to function following a mechanical effect exerted by the bullet during its passage, a projectile or grenade thus equipped, cannot be fired with propulsion cartridges without bullets, except with a very low efficiency, and, therefore, a profound modification of the firing conditions.
In order to remedy these disadvantages and to provide a solution to the aforementioned problems a bullet passage plug has already been proposed which can easily be traversed by the aforementioned bullet, and which closes after the passage of the bullet in order to prohibit all passage of propulsive gases.
Notwithstanding that the propulsive gases produced by the firing of the cartridge result in the launching of the aforementioned projectile or grenade by exerting an adequate force on the closed bullet passage after the passage of the bullet, it has been proven more efficient to provide an additional charge which can add to the effect of the propulsive gases mentioned above in order to result in a more considerable force on the bullet passage plug particularly a larger launching force.